Reviews of the iPhone 6s have been hitting all of the usual technology sites in the last couple of days. And one of the things that many users are wondering about is the battery life of the iPhone 6s. Is the battery in the iPhone 6s better or worse than the iPhone 6?

I scoured the Web to find out what reviewers thought of the battery performance of the iPhone 6s, and I've included their thoughts below to make it easy for you to skim through the sections of reviews that just cover the battery.

You can also click through to each site to read its entire review of the iPhone 6s.

John Gruber at Daring Fireball got about the same battery life in the iPhone 6s as the iPhone 6:

Also seemingly unchanged from last year: the effective battery life of the device. I didn’t perform any sort of battery life tests, but in heavy daily usage, the iPhone 6S felt like it got the same battery life as the iPhone 6 I’ve been using for a year. No better, no worse. Like last year, the iPhone 6S Plus clearly gets way better battery life than the regular 6S, simply because it has room for a far larger battery.

New-number iPhones (4, 5, 6) are about showing off Apple’s design prowess. The S models are about showing off Apple’s engineering prowess. Storage capacities and battery life are unchanged from last year’s iPhones. Everything else — the materials they’re made from, the performance of their custom CPU/GPU, the quality of the cameras, the smoothness of the user interface — is noticeably, tangibly improved.

What is cool is that Apple now provides more info as to what's going on behind the scenes with the battery. Not only does it tell you what's been nabbing all your power in the last 24 hours / week, but it will also tell you how much of that was background and foreground effort.

That means if you see Facebook is taking most of your battery and constantly updating when you're not looking, you can disable it to get back that life (and not really lose much functionality).

That doesn't mean I was able to really get a lot of battery life out of the iPhone though. Even when I'd managed to get rid of the apps that were taking the most power, things like Apple Music would pop up and take their space, despite not being in the foreground.

The reason could have been shown off at the Apple launch itself: the iPhone 6S was seen in a video sporting 1715mAh battery, which is much lower than the 1810mAh offering placed in the iPhone 6 - that additional 3D Touch circuitry certainly seems to have come at a price.

Joanna Stern at the Wall Street Journal still wanted a bigger battery:

Let’s get this out of the way first. The No. 1 thing people want in a smartphone is better battery life. And the iPhone 6s doesn’t deliver that.

The 4.7-inch 6s will get you through the day, but you’ll struggle to make it til bedtime with moderate to heavy use. And it seemed to drain even faster than my 6 when I used the new processor-intensive camera features like Live Photos. The bigger 5.5-inch 6s Plus lasted longer and is the best choice if you’re a heavy user and want some juice left over at the end of the day. (Of course, battery life on any smartphone generally degrades over time.)

Still, there is no battery improvement over last year’s iPhone 6 models. In our grueling test, which loops a series of websites with brightness set at around 65%, I found the 6s and 6s Plus get no more—but also no less—battery life than their predecessors. (iOS 9 itself adds an hour of savings to the iPhone 6, and has Low Power Mode.) Strangely, although Apple says that the 6s Plus gets hours more battery life than the 6s, repeated testing on multiple devices reveals a slimmer difference. In a Web surfing test, the 6s on average lasted for 8 hours, while the 6s Plus went 20 minutes longer. In a video playback test, the difference was an hour.

Here’s the real kicker: To accommodate the phone’s new touchscreen technology, the new iPhone 6s is an unnoticeable 0.01 inches thicker, and a slightly noticeable half-ounce heavier, but the battery is actually slightly smaller. I’d happily buy a thicker iPhone, if it meant more time away from the power outlet.

Matthew Panzarino at Tech Crunch felt that Apple succeeded in matching the battery life of the iPhone 6 and 6 Plus:

Battery life is only worth mentioning in that there has been some talk about a slight reduction in battery size for the iPhone 6s. I don’t know about that, but I can say that battery life is spec’d to be exactly the same by Apple and that’s the way it felt.

Going from a heavy day of email, shooting pictures of my kid, meetings at companies like Facebook, video at a baseball game and late night Slacking all felt roughly identical on the iPhone 6 Plus and iPhone 6s Plus. No appreciable difference. To bed at around 20 percent with no charging during the day. If there’s any change in battery size, it’s likely more than made up for by the new power-saving features in iOS 9.

Walt Mossberg at Recode noted the usefulness of Low Power Mode in iOS 9:

In two weeks of heavier-than-normal use (because I was testing, testing, testing) the iPhone 6s never died on me before I was ready to end my day. Even after 15 hours, there was typically 10 percent or so of battery life left in the tank.

Also, as part of iOS 9, which is available for older models as well, Apple, like Android phone makers before it, has built in a “low power mode” that squeezes in an extra hour or so of battery life. It does this by cutting speed, brightness and app activity in the background. You can still make calls, send and receive emails and texts, and browse the Web in this mode.

Stuart Miles at Pocket Lint was impressed with the battery of the iPhone 6s:

You would expect all these new features to hammer the battery, but they don't. Apple has not only improved the battery performance with iOS 9, but despite a 5 percent dip in battery capacity compared to the iPhone 6, we've seen comparable life per charge.

One thing that will help the iPhone 6S last longer than the previous iPhone is the introduction of Low Power Mode. Available to all iPhones running iOS 9 rather than a specific new feature of the 6S, the new mode shuts down all non-essential functions to extend the battery life of the phone. You're asked if you want to turn the Low Power Mode on with 20 per cent remaining and again at the 10 per cent mark, giving you plenty of juice to still be able to order that Uber home at the end of the evening.

In our tests we've been really impressed with longevity. Our iPhone 6S used only 15 per cent of battery in 12 hours with it on, while an iPhone 6S Plus lasted a similar 24 hours for 29 per cent of battery. As ever with a phone, hammer it with the gaming apps and you'll squeeze that juice out faster, but it's all relative.

Matt Hill at Digital Spy also appreciated the battery life of the iPhone 6s:

Battery life is unlikely to give you grief, though. The iPhone 6S's battery's size might have dropped from its predecessor's 1,810mAh to 1,715mAh, but amazingly you won't feel the cutbacks. Instead, the phone's staying power is hugely impressive, seeing us through around 27 hours on a single charge without too much trouble. This isn't playing gentle with usage, either, handling some serious web-browsing, email-writing, camera-using, game-playing action, the phone strolls through a full day.

There's a new Low-Power Mode to help eke things out a little further, too, if even that's not enough. A pull across from its Android challengers, this feature cuts background power usage from apps and mail clients when you drift below 20% charge. It works well, too, successfully tripling what would have been our last 2 hours of life support. Importantly, when the 6S does slump into the battery danger zone, recharge times are impressively speedy, returning to full charge again in a little over an hour.

Based on the reviewer comments I included above, I think it's safe to say that the battery life of the iPhone 6s is looking very good. Apple didn't seem to add to it, but they also didn't seem to take any away from it. And I think that's very good news for those who are considering buying the iPhone 6s.

I'll know more myself when my own iPhone 6s arrives Friday. But so far I'm fairly impressed with what I've seen about the battery life of the iPhone 6s. I think it's going to work very well for me, and I can't wait to get my hands on it.

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Jim Lynch is a technology analyst and online community manager who has also written for many leading industry publications over the years, including ITworld, InfoWorld, CIO, PCMag, ExtremeTech, and numerous others.

The opinions expressed in this blog are those of Jim Lynch and do not necessarily represent those of IDG Communications, Inc., its parent, subsidiary or affiliated companies.